1. Used as a replacement for any word that a person may find too difficult to immediately think of due to exceptionally exciting or dramatic circumstances.

2. Used/inserted when the name of an item or event slips your mind.

1. (A ninja and a dragon are having an awesome battle on the moon as two friends watch through telescopes)
Friend 1: "Mate, can you see that ninja, he's totally ninja punching a bloody crestive!"
Friend 2: "Yeah, that dragon is getting the beating of his life!"

2. Joshua Badger: " I was eating this totally rad salad the other day and then I found there were these little green oval crestives buried at the bottom"
Nicholas Stock: "They were olives."